Japanese cedar pollinosis: discovery, nomenclature, and epidemiological trends.

The history of pollinosis in Japan before the discovery of Japanese cedar pollinosis was presented in part I in this paper. Until early 1960s, it was believed that there was no pollinosis in Japan except one case of ragweed pollinosis. The summary of how the Japanese cedar pollinosis was discovered and named was presented in part II, by referring to the paper in which we reported the presence of Japanese cedar pollinosis for the first time. The epidemiology after the discovery of Japanese cedar pollinosis was presented in part III. The number of the patients suffering from Japanese cedar pollinosis gradually increased since the 1970s. The annual incidence rate of the pollinosis had correlations with the dispersed pollen count per year. The prevalence rate of the patients with Japanese cedar pollinosis increased from 16.2% in 1998 to 26.5% in 2008 by the nationwide survey. The prevalence rate of the patients with Japanese cedar pollinosis in Tokyo metropolitan area was 10% from 1983 to 1987, 19.4% in 1996, and 28.2% in 2006. The prospects of current research and future studies were discussed in parts IV and V.

[Consultation patterns among Japanese cedar pollinosis subjects at an urban clinic report 2: a 20-year experience (1990-2009) in Chiyoda Ward, Tokyo].

To determine the consultation patterns of Japanese cedar pollinosis subjects during the pollen dispersal season, we surveyed those treated at a private clinic in Chiyoda Ward, Tokyo, from 1990 to 2009. We also studied the relationship between subject numbers and pollen count. The above relationship correlated highly with linear regression equation y = 0.0897x + 627.47 with R² = 0.7851 (p < 0.001). The relationship from 1994 to 2009, when the study began in early January, correlated highly with logarithmic regression equation y = 257.43Ln(x) - 1014.8 with R² = 0.9542 (p < 0.001). Based on these results, we concluded that estimated pollen count helps predict the year's Japanese cedar pollinosis subject numbers very highly accurately. Numbers of subjects returning did not correlate well with pollen count, and continued to decrease each year. Return visits averaging 2.6 in 1990 gradually decreased to 0.73 in 2006--a reduction we attributed to long-term medication and the increased self-payment proportion in medical expenditures.

[Medical consultation dynamics in Japanese cedar pollinosis patients at an office building clinic in central Tokyo].

To clarify medical consultation dynamics in Japanese cedar pollinosis patients visiting an office building clinic in an office block in central Tokyo, we surveyed number of patient at a private ENT clinic in Chiyoda-ku, Tokyo, during the Japanese cedar pollen season from 1990 to 1999. Based on questionnaires and CAP RAST tests in 1995, we studied the profiles of Japanese cedar pollinosis patients and determined positive rates of noncedar antigens. The gender ratio in 1995 was 674 men versus 501 women, most frequently men in their 40s and women in their 20s. Of these, 79.2% worked in Chiyoda-ku and Chuo-ku, but only 1.9% lived in these districts. Positive rates of noncedar antigens in 232 who received simultaneous CAP RAST tests were 64.7% for Japanese cypress, 38.3% for house dust, 35.3% for Dermatophagoides pteronyssinus, 34.4% for Epidermoptidae spp, 19.8% for mixed grasses, and 10.3% for mixed weeds (asteraceous plants). Patients positive for cedar alone were 19.0% and positive for both cedar and cypress but negative for other antigens were 23.3%; about 60% of these were suspected of multiple sensitization to antigens other than cedar and cypress. The number of pollens and patients were summarized weekly and compared. Those paying a first visit were peaked with an increase in pollen in the first week of March almost every year; second visits peaked 1 or 2 weeks later than the first visit. Little increase in first visit was noted even with increasing pollen dissemination from the latter half of March. The relationship between the number of pollen and patients each year from 1990 to 1999 correlated highly with the linear regression equation y = 0.1005x + 547.07 with R2 = 0.7562. The relationship between square roots of the number of pollen and patients each year for 5 year from 1995 to 1999 correlated very highly with the linear regression equation y = 11.167x + 376.72 with R2 = 0.9941. We concluded that the number of patients may be predicted with substantially higher accuracy based on the estimated amount of pollen in a given year.